1. Field of the Invention
The present invention relates to a matrix switcher used in broadcasting facilities or the like, and particularly relates to the matrix switcher having an interface for a general-purpose network.
2. Description of the Related Art
Matrix switchers are apparatuses to perform switching of a video signal, an audio signal, a control signal of a device and the like in broadcasting facilities (for example, refer to Japanese Patent No. 3094654 and Japanese Unexamined Patent Application Publication No. 2002-77253). A matrix switcher basically includes a switcher unit and a control unit. The switcher unit includes a plurality of input signal lines and a plurality of output signal lines intersected, and a connection switch made of a semiconductor device is provided at each intersection. An operator performs a switching operation on the matrix switcher by using a dedicated remote controller, and the control unit switches a connection relation between the input signal lines and output signal lines in the switcher unit upon receiving a switching command from the remote controller.
When a program is on the air or recorded, video/audio signals output from a number of video cameras and microphones in a studio or at a remote scene, video/audio signals reproduced from a VTR and a video server, signals for controlling devices (e.g., program transmission apparatus and VTR), and the like are input to the switcher unit in the matrix switcher where destinations of those input signals are switched.
Broadcasting facilities or the like typically use a plurality of matrix switchers in combination such that a matrix switcher is used with newly installed another matrix switcher. In such case, typically the matrix switchers and the above-described remote controller have been connected to a dedicated communication line (referred to as “S-BUS”) as described in paragraphs [0023] through [0026], for example, of Japanese Patent No. 3094654. All the apparatuses connected on the S-SUB are categorized into one “primary station” and the remaining “secondary stations”, in which the primary station performs communication with respective secondary stations by polling and the primary station also relays communication performed between the secondary stations. Further, a terminal apparatus connected to the S-BUS has typically performed setup of a matrix switcher.